Periodontists have observed a significant incidence of "sterile" gingival abscesses that contain corn husks. The possibility of a causal relationship between the pathogenesis of this gingival inflammation and impacted food particles is being studied. Saline extracts of a variety of nuts and corn have therefore been tested and found to be mitogenic for lymphocytes, to stimulate the production of factors chemotactic for macrophages and to release histamine from basophiles of allergic subjects. The likelihood that some foods can directly cause tissue inflammation by nonspecific mitogenic activation of lymphocytes is being further studied.